Suggestions for dealing with a "frozen" track cog?

I recently decided to switch down from a a 16 to 15-tooth cog on my
road-conversion fixie. After I picked up the new cog and pulled the
lockring, I spent the better part of an hour wrestling with the old
cog, pulling as hard as I could on the chain whip in hopes of freeing
it. So far, I've been completely unsuccessful.

It is entirely possible that I'm just not strong enough and will need
some additional leverage, (or the help of a friend with more upper body
strength) but I just wanted to see what other people's experiences had
been when switching out track cogs on relatively heavily-used
"commuter" fixed gear bikes. I assume that any manual force I could
exert on the wheel (so long as it's relatively in-line with the normal
rotational and braking forces) shouldn't do any damage to it, but
wonder if I should be trying solvents or something, rather than
continuing to attempt the brute-force approach.

Any recommendations would be appreciated.

Lennon

P.S.: As long as I've got the fixie riders' attention, how about a
quick poll? What gearing do you run? If I succeed in this switch, I'll
be going from 42/16 to 42/15, and thinking about switching to a 44t
chainring as my next "upgrade".

Try heating it with a heat gun or even a high-output hair drier. Did you
grease the threads before you installed it?

--

alan...42x20 commuter with lights, fenders, panniers, etc.

Anyone who believes in a liberal media has never read the "Daily Oklahoman."


"rcoder" wrote in message
ups.com...
I recently decided to switch down from a a 16 to 15-tooth cog on my
road-conversion fixie. After I picked up the new cog and pulled the
lockring, I spent the better part of an hour wrestling with the old
cog, pulling as hard as I could on the chain whip in hopes of freeing
it. So far, I've been completely unsuccessful.

It is entirely possible that I'm just not strong enough and will need
some additional leverage, (or the help of a friend with more upper body
strength) but I just wanted to see what other people's experiences had
been when switching out track cogs on relatively heavily-used
"commuter" fixed gear bikes. I assume that any manual force I could
exert on the wheel (so long as it's relatively in-line with the normal
rotational and braking forces) shouldn't do any damage to it, but
wonder if I should be trying solvents or something, rather than
continuing to attempt the brute-force approach.

Any recommendations would be appreciated.

Lennon

P.S.: As long as I've got the fixie riders' attention, how about a
quick poll? What gearing do you run? If I succeed in this switch, I'll
be going from 42/16 to 42/15, and thinking about switching to a 44t
chainring as my next "upgrade".

On Tue, 01 Feb 2005 12:09:07 -0800, rcoder wrote:

What gearing do you run? If I succeed in this switch, I'll
be going from 42/16 to 42/15

I do 42x16 on my single, it's hilly round here, and it's also my beer run
bike, so gotta keep the gearing reasonable.

as for getting the cog off, some penetrating lubricant never hurt nobody...

rcoder wrote:
I recently decided to switch down from a a 16 to 15-tooth cog on my
road-conversion fixie. After I picked up the new cog and pulled the
lockring, I spent the better part of an hour wrestling with the old
cog, pulling as hard as I could on the chain whip in hopes of freeing
it. So far, I've been completely unsuccessful.

It is entirely possible that I'm just not strong enough and will need
some additional leverage, (or the help of a friend with more upper
body

Additional leverage is the key. Try placing the cog in a vise (use
blocks of wood to prevent damage to the cog) and turning the wheel
instead of holding the wheel and trying to turn the cog. Don't
over-tighten the vise or you might warp the cog and cause damage to the
hub. The extra leverage gained by turning the wheel instead of the cog
should be enough to pop it loose.

Good luck!

-Buck

"Buck" wrote(clip)Try placing the cog in a vise (use blocks of wood to
prevent damage to the cog) (clip)
^^^^^^^^^^^^^^^
I would also consider wrapping some chain around the cog, and then holding
with blocks in the vise. That will put the clamping pressure on the roots
of the teeth instead of the tips.

In article . com,
"rcoder" writes:

I recently decided to switch down from a a 16 to 15-tooth cog on my
road-conversion fixie. After I picked up the new cog and pulled the
lockring, I spent the better part of an hour wrestling with the old
cog, pulling as hard as I could on the chain whip in hopes of freeing
it. So far, I've been completely unsuccessful.

It is entirely possible that I'm just not strong enough and will need
some additional leverage, (or the help of a friend with more upper body
strength) but I just wanted to see what other people's experiences had
been when switching out track cogs on relatively heavily-used
"commuter" fixed gear bikes. I assume that any manual force I could
exert on the wheel (so long as it's relatively in-line with the normal
rotational and braking forces) shouldn't do any damage to it, but
wonder if I should be trying solvents or something, rather than
continuing to attempt the brute-force approach.

Any recommendations would be appreciated.

Just on the off-chance you're attempting this with the wheel off
the bike and the tire off the wheel, and standing the naked rim
upright on the floor:

try putting the tube & tire back on and inflating it. That'll
give your wheel-supporting hand a better grip, and the tire
will help keep the wheel from sliding while you reef on the
chain whip.

Otherwise ... good ol' Liquid Wrench, I guess.


cheers,
Tom

--
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Above address is just a spam midden.
I'm really at: tkeats [curlicue] vcn [point] bc [point] ca

"Buck" wrote:
"Try placing the cog in a vise (use blocks of wood to prevent damage to the
cog)"

It is better to place the chainwhip or cog tool in the vise and then turn
the wheel. If you put the cog in the vise the force of the vise will pinch
the cog against the hub.


--
Mike Murray